JP2007270894A - Sliding member and method for forming coating layer thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding member improving sliding characteristics of base material by coating layer comprising solid lubricant and provide the coating layer of low friction coefficient and excellent in wear resistance. <P>SOLUTION: The coating layer 7 has a structure of laminated solid lubricant plate shape crystal particle 3, and contains 8 of 10 wt.% or less binder resin for binding the solid lubricant plate shape crystal particle 3. The lubricant plate shape crystal particle has a crystal structure having (001) surfaces (provided that 1 is an integer of 1 or greater) laminated in parallel, and orientation index of the (001) surface is 90% or higher at least on the sliding surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sliding member in which a coating layer made of solid lubricant plate-like crystal particles is attached to the surface of a base material, and a method for forming the coating layer.

  In a sliding bearing (sliding member) for an automobile engine, an aluminum bearing alloy or a copper bearing alloy is generally used as a sliding layer. In recent years, automobile engines have been increasing in output and rotation, while demands for improvement in fuel consumption are high, and therefore, sliding bearings are required to have low friction. In particular, low friction under boundary lubrication is required for vehicles that frequently start and stop the engine, such as hybrid vehicles.

In order to cope with the demand for low friction under boundary lubrication, it is effective to provide a coating layer made of a solid lubricant to improve the surface of the slide bearing. For the modification of bearing surfaces with solid lubricants, there is a known technology that applies shot peening and shot blasting techniques to cause solid lubricant particles to collide with the sliding bearing surface and adhere to the bearing surface by the impact energy. (For example, refer to Patent Documents 1 and 2).
JP-A-11-131257 JP 2002-339083 A

  Patent Document 1 described above describes that a zinc lubricant powder having an average particle diameter of 100 μm is made to collide with a base material to diffuse and penetrate zinc into the base material using a blast device. In Patent Document 2, molybdenum disulfide having an average particle diameter of 1 to 20 μm and a purity of 95% or more is collided with an engine piston or a cylinder bore at a projection speed of 100 m / s or more to form a coating layer. It is described that an excellent effect of reducing the friction coefficient is obtained by this coating layer.

  However, in the case of forming a coating layer made of solid lubricant by causing solid lubricant particles to collide with the surface of the substrate, a layer rich in solid lubricant particles can be formed. Since it is work-hardened, the conformability is lowered and the non-seizure property is lowered. In addition, in the case of causing the solid lubricant particles to collide with the base material, the solid lubricant particles diffuse into the base material, or the solid lubricant particles are driven into and adhered to the base material at the moment of impact. Since the film is formed, only a very thin coating layer can be formed and wears out early.

  The present invention has been made in view of the above circumstances, and a first object thereof is to provide a sliding member having a low coefficient of friction and excellent wear resistance. The object of the present invention is to provide a method for forming a coating layer for a sliding member that can form a coating layer rich in a solid lubricant on the substrate surface of the sliding member without subjecting the surface of the substrate to work hardening.

Molybdenum disulfide, graphite, tungsten disulfide, and boron nitride are often used as solid lubricants. These have the form of plate-like crystal particles, and the plate-like crystal particles have a layered crystal structure in which layers having a (00l) plane as a maximum plane in the Miller index are stacked in parallel. For example, the plate-like crystal particles of molybdenum disulfide have a structure in which layers of MoS ₂ molecules connected in a direction parallel to the xy plane are stacked in the z-axis direction as shown in FIG. Only weak van der Waals forces are acting between layer 1 and layer 2. As shown in FIG. 6, such solid lubricant plate crystal particles 3 have a plate-like appearance shape having a relatively thin thickness.

  When plate-like crystal particles with a lamellar crystal structure are present as a solid lubricant in the coating layer of the sliding member and the shear force acts between the layers in the plate-like crystal particles as the mating material moves, the van der Waals force is easily Overcoming the above, slip occurs between the layers. This interlaminar slip is peculiar to a substance having a layered crystal structure, and its friction coefficient is extremely low. This is the mechanism by which the sliding member has low friction when plate-like crystal particles are used as the solid lubricant.

  The present inventor has the mechanism of low friction of the solid lubricant plate-like crystal particles having a layered crystal structure as described above. Therefore, in the solid lubricant plate-like crystal particles constituting the coating layer, If the surface between them is parallel to the direction of movement of the counterpart material, that is, the surface of the coating layer, it is predicted that the friction can be further reduced, and the present invention has been made.

(1) Sliding member according to the present invention <Prerequisite constitution of the present invention>
The present invention is directed to a sliding member having a configuration in which a coating layer having a sliding surface is attached to the surface of a substrate.

  FIG. 2 shows a partial cross section of a radial bearing sliding member (slide bearing) 4 as an example of the sliding member. The radial bearing sliding member 4 includes, for example, a back metal layer 5 and a back metal. A bearing alloy layer 6 lined on the layer 5 and a coating layer 7 formed on the bearing alloy layer 6 as a base material are formed into a three-layer structure. The radial bearing sliding member 4 is formed in a semi-cylindrical shape as shown in FIG. 4 or a cylindrical shape although not shown in the drawing. The radial bearing sliding member 4 has a two-layer structure in which a bearing alloy layer 6 is formed on a back metal layer 5 as shown in FIG. 5, and a bearing alloy layer shown in FIG. A multilayer structure in which an overlay layer is further formed on the surface of 6 is often used, but there is also a single-layer structure having only a bearing alloy layer. Sliding members used for thrust bearings are merely flat, and there are single-layer, double-layer, and multi-layer structures as in radial bearings. In the single-layer structure and the two-layer structure, the bearing alloy layer corresponds to the base material, and in the multi-layer structure, the overlay layer corresponds to the base material.

Further, the present invention can be applied to a sliding member having no bearing alloy layer, that is, a sliding member constituted only by a member corresponding to the back metal layer 5 in FIG. An equivalent member becomes a base material. The back metal equivalent member is not limited to metal, and may be made of resin.
As for the sliding member which this invention makes object, the coating layer has adhered to the surface of the base material. Accordingly, the counterpart material slides on the surface of the coating layer. The surface of the coating layer on which the counterpart material slides is called a sliding surface.

<Characteristic configuration of the sliding member of the present invention>
The sliding member of the present invention is premised on the sliding member having the above-described configuration, and the coating layer is formed by laminating solid lubricant plate crystal particles and bonding the solid lubricant plate crystal particles. The solid lubricant plate-like crystal particles have a crystal structure in which (00l) planes (where l is an integer of 1 or more) are stacked in parallel, and at least the sliding resin is contained. In the dynamic surface, the (001) plane has an orientation index of 90% or more (claim 1).

The sliding member of the present invention has a low coefficient of friction and excellent wear resistance.
In the present invention, the coating layer is formed by laminating solid lubricant plate crystal particles on the surface of the substrate. For this reason, the coating layer can be formed thick by increasing the number of laminated layers of the solid lubricant plate crystal particles. As the solid lubricant plate-like crystal particles, any one or more of plate-like crystal particles such as molybdenum disulfide, graphite (graphite), tungsten disulfide, boron nitride and molybdenum trioxide can be used. 2). These solid lubricant plate crystal particles are hexagonal.

  FIG. 1 illustrates a state in which solid lubricant plate crystal particles 3 are laminated on the surface of a base material, for example, a bearing alloy layer 6. The gaps between the stacked solid lubricant plate crystal particles 3 are filled with the binder resin 8, and the binder resin 8 bonds the solid lubricant plate crystal particles 3 to each other. The binder resin 8 is also present between the solid lubricant plate crystal particles 3 and the bearing alloy layer 6, and adheres the solid lubricant plate crystal particles 3 to the bearing alloy layer 6.

In this specification, the crystal form of the solid lubricant plate crystal particles is expressed by Miller index (hkl), and the orientation index of the crystal plane (00l) plane is defined by the following formula. L is an integer of 1 or more.
(00l) plane orientation index (%) = [ΣR (00l) / ΣR (hkl)] × 100
However, R (00l) means the X-ray intensity of the (00l) plane, ΣR (00l) is the sum of the detected X-ray intensity of the (00l) plane, ΣR (hkl) is the (hkl) plane, That is, the sum of the X-ray intensities of all detected surfaces.

  The closer the orientation index is to 100%, the more crystal planes oriented in the (001) plane. The solid lubricant plate crystal particles have a layered crystal structure in which the layers in the particles are stacked with the (00l) planes parallel to each other. In the following description, the boundary surface between the layers of the plate-like crystal particles is referred to as an interlayer surface. The interlayer surface is parallel to the (001) plane. In the present invention, at least on the sliding surface, the (001) plane orientation index of the solid lubricant plate crystal particles is 90% or more. The coating layer having a high orientation index of the (00l) plane tends to have a large number of solid lubricant plate crystal grains in which the (00l) plane is stacked in parallel to the sliding direction.

  As described above, the coating layer has a laminated structure of solid lubricant plate crystal particles, and the binder resin exists so as to fill the gaps between the solid lubricant plate crystal particles. The binder resin is harder and higher in strength than the solid lubricant plate crystal particles. Further, since the resin for binder has elasticity, it is deformed when a load is applied from the counterpart material, and the sliding surface comes into contact with the counterpart material and receives the load.

  When the mating material slides on the sliding surface under boundary lubrication, the mating material slides in contact with the solid lubricant plate crystal particles that occupy a large area of the sliding surface. Along with this, a shearing force is generated in the solid lubricant plate crystal particles. As a result, slippage (interlayer slip) occurs on the interlayer surface parallel to the moving direction of the counterpart material in the solid lubricant plate crystal particles. At this time, since only a very weak van der Waals force is acting between the layers of the plate-like crystals, an interlayer slip easily occurs with a very small shearing force. As a result, even when the mating material is under boundary lubrication, the counterpart material slides smoothly with only a very weak frictional resistance. In addition, since the load of the counterpart material is hard and can be received by the binder resin having a high strength, premature wear of the coating layer (solid lubricant plate-like crystal particles) is prevented.

  Content of the resin for binders which exhibits the above effects is 10 mass% or less. If it exceeds 10% by mass, a high orientation index cannot be realized, and the effect of low friction of the solid lubricant plate crystal particles cannot be expected. 0.5 mass% or more is preferable. The content of the binder resin is more preferably 2 to 7% by mass (Claim 3). As the binder resin, either a thermoplastic resin or a thermosetting resin may be used. PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), PA (polyamide resin), PAI (polyamideimide resin), and PF (phenol resin) are particularly preferable.

(2) Manufacturing method of sliding member by this invention The coating layer of the sliding member of this invention is formed by the following methods.
That is, in a method for forming a coating layer of a sliding member in which a coating layer having a sliding surface is attached to the surface of a base material, a solid lubricant plate crystal having a crystal structure in which (00l) planes are stacked in parallel on an adhesion medium. Particles are freely attached together with the binder resin powder, and the adhesion medium in which the solid lubricant plate crystal particles and the binder resin powder are freely adhered is applied to the substrate surface while applying pressure to the substrate surface. By sliding the surface, the solid lubricant plate crystal particles are rubbed against the substrate surface so that the (00l) plane of the solid lubricant plate crystal particles is parallel to the substrate surface. The solid lubricant is adhered together with the binder resin powder, and the adhesion medium is slid while applying pressure to the surface of the solid lubricant plate crystal particles adhered to the substrate surface. And adhering the solid lubricant plate crystal particles together with the binder resin powder on the surface of the crystal particles and laminating the solid lubricant plate crystal particles and the binder resin powder, By heating the base material and / or adjusting the sliding speed of the adhesion medium to generate frictional heat, the binder resin powder is made into a semi-molten or molten state to form the solid lubricant plate Impregnation between crystal grains.

The method for forming a coating layer for a sliding member according to the present invention can form a coating layer rich in a solid lubricant on the surface of the base material of the sliding member without subjecting the base material surface to work hardening.
According to this manufacturing method, when an adhesion medium in which solid lubricant plate-like crystal particles and binder resin powder are freely adhered is slid while applying pressure to the substrate surface, the solid lubricant plate-like crystal particles are formed on the basis. Roll while rubbing the material surface. At this time, the solid lubricant plate crystal particles move while being aligned because of the plate shape as described above, and the (00l) plane is in contact with the substrate surface with respect to the substrate surface on which the strongest frictional force acts. Align so that they are oriented in parallel. The solid lubricant plate-like crystal particles rub against the substrate surface to form a chemical reaction field, so that a tribochemical reaction takes place, thereby connecting the layers of the solid lubricant plate-like crystal particles. Bonded to the substrate surface with a force stronger than the Delwars force. The binder resin powder is also infiltrated and held between the solid lubricant plate crystal particles attached to the substrate surface.

  Further, the solid lubricant plate-like crystal particles attached to the medium are sequentially laminated on the solid lubricant plate-like crystal particles attached to the surface of the substrate, and the binder resin powder is formed into those solid lubricant plate-like particles. It enters and is held between crystal grains. FIG. 1 shows a state in which a plurality of layers of solid lubricant plate crystal particles 3 </ b> B are attached on the first layer solid lubricant plate crystal particles 3 </ b> A attached to the surface of the bearing alloy layer 6.

In the process of adhering such solid lubricant plate crystal particles, the base material is heated and / or the sliding speed of the adhering medium is adjusted to generate frictional heat, so that the binder resin powder is in a semi-molten state. Alternatively, it is made into a molten state and impregnated between the solid lubricant plate crystal particles. Thereby, the solid lubricant plate crystal particles are fixed to the surface of the base material, and the solid lubricant plate crystal particles are bonded to each other.
When the binder resin is a thermosetting resin, after the binder resin is impregnated between the solid lubricant plate crystal particles, the binder resin is further heated to cause a cross-linking reaction, thereby binding force of the binder resin. Can be increased (curing treatment). In addition, when the resin for binders is thermoplastic, if it cools, it will solidify.

  In the coating layer formed by the production method of the present invention, with respect to the orientation of the solid lubricant plate-like crystal particles on the sliding surface, only the peak of the (001) plane crystal plane such as the (002) plane or the (004) plane is present. Not seen (Figure 8). On the other hand, on the sliding surface of the coating layer formed by a manufacturing method different from the present invention, the peaks of crystal planes such as the (101) plane, the (102) plane, and the (103) plane are also detected other than the (001) plane. (FIG. 9). This will be described later.

Hereinafter, an embodiment in which the present invention is applied to a sliding member for a radial bearing (hereinafter simply referred to as a sliding bearing) will be described with reference to the drawings. As shown in FIG. 4, the plain bearing 4 is formed in a semi-cylindrical shape. As shown in FIG. 2, the plain bearing 4 has a multilayer structure including a back metal layer 5, a bearing alloy layer 6, and a coating layer 7.
Since the solid lubricant plate-like crystal particles constituting the coating layer itself are soft, they are excellent in foreign matter embedding properties, good conformability, and excellent in non-seizure properties.

  From the above, in the sliding member of the present embodiment, the mating material slides smoothly with low friction by the solid lubricant plate crystal particles while preventing early wear of the coating layer by the resin for the binder. It is excellent in both wear resistance and non-seizure property. The manufacturing method of this slide bearing 1 is as follows. First, as shown in FIG. 5, a bearing alloy layer 6 is lined on the back metal layer 5 to form a bimetal 9. Then, a strip-shaped piece is cut out from the bimetal 9, and this strip-shaped piece is bent into a semi-cylindrical shape to obtain a semi-cylindrical shaped body. Then, the surface of the bearing alloy layer 6 that is the inner peripheral surface of the semicylindrical shaped body is finished by boring, and then washed and degreased to form a coating layer 7 on the bearing alloy layer 6 to obtain the slide bearing 4. .

The coating layer 7 is composed of solid lubricant plate-like crystal particles 3 laminated on the surface of the bearing alloy layer 6, and in this coating layer 7, as shown in FIG. A binder resin 8 for bonding to the bearing alloy layer 6 and for bonding the solid lubricant plate crystal particles 3 to each other is included.
As shown in FIG. 3, the attachment device 10 for laminating the solid lubricant plate crystal particles 3 on the surface of the bearing alloy layer 6 is attached to a rotating body 12 as a core body detachably attached to the rotating shaft 11. In addition, one end side of the plurality of adhesion media 13 is fixed. The adhering medium 13 is made of a flexible member such as cloth, non-woven fabric, paper, leather, plastic, or fibrous metal, and is formed in an arc plate shape having a width slightly larger than the width of the sliding bearing 4 here. Yes. The adhesion medium 13 is preferably a member having a large surface area with irregularities on the surface. This is because a large amount of solid lubricant plate crystal particles and binder resin powder can be freely adhered to the adhesion medium 13 at a time.

  In order to form the coating layer 7 on the inner peripheral surface of the slide bearing 4 by the adhesion device 10, first, the two slide bearings 4 are butted in a cylindrical shape and are arranged so as to be concentric with the rotary shaft 11. (Not shown). Then, solid lubricant plate-like crystal particles having a layered crystal structure in which (001) faces are stacked in parallel on a plurality of adhering media 13 fixed to the rotator 12, for example, molybdenum disulfide particles, and a binder resin powder For example, a large amount of phenol resin powder is freely adhered, and the rotating body 12 is attached to the rotating shaft 11 so that the adhering medium 13 is accommodated in the two slide bearings 4 that are abutted in a cylindrical shape.

  Then, the rotating shaft 11 is rotated by a motor (not shown). Then, the tip portion as the other end of the adhesion medium 13 rotates so as to slide while receiving pressure on the inner peripheral surface of the bearing alloy layer 6 which is the inner peripheral surface of the slide bearing 4 under the centrifugal force accompanying the rotation. At this time, the sliding speed of the adhesion medium 13 on the inner peripheral surface is preferably 5 m / second or more. The rotation of the adhesion medium 13 causes the molybdenum disulfide particles and the phenol resin powder adhering freely to the adhesion medium 13 to frictionally move while pressure is applied between the adhesion medium 13 and the inner peripheral surface. The molybdenum particles are oriented so that the interlayer surface is parallel to the surface of the bearing alloy layer 6 (because the (001) plane which is the maximum surface is stable to be parallel to the moving direction), and A tribochemical reaction occurs and adheres to the surface of the bearing alloy layer 6. At this time, the phenol resin powder is also impregnated between the solid lubricant plate crystal particles adhering to the bearing alloy layer 6.

Further, when the adhesion medium 13 rotates, another molybdenum disulfide particle is deposited on the molybdenum disulfide particles adhering to the surface of the bearing alloy layer 6 and the disulfide disulfide below the (00l) surface (interlayer surface). The molybdenum particles are oriented so as to be substantially parallel to the (001) plane of the molybdenum particles and are sequentially laminated. Also at this time, the phenol resin powder is impregnated between the laminated solid lubricant plate crystal particles.
As described above, the coating layer 7 composed of the layer of molybdenum disulfide particles laminated on the bearing alloy layer 6 is formed. When the thickness of the coating layer 7 reaches a desired thickness of 1 μm or more, the adhesion process is finished. To do. In addition, the operation time of this adhesion | attachment process is suitably determined according to the thickness of the coating layer 7 to desire.

When the coating layer 7 is formed, a jig (not shown) is preheated to heat the sliding bearing 4 fixed to the jig, or the sliding speed of the adhering medium 13 on the surface of the sliding bearing 4 is appropriately adjusted to cause friction. By controlling the degree of heat generation, the phenol resin powder is made semi-molten or molten to have fluidity. Then, the phenol resin that has entered between the bearing alloy layer 6 and the solid lubricant plate crystal particles thereon and between the solid lubricant plate crystal particles fills the gaps between them. . Thereafter, the sliding bearing 4 is heated to a predetermined temperature to cause the phenol resin to undergo a crosslinking reaction. Thereby, the phenol resin which is a thermosetting resin is cured, and the solid lubricant plate crystal particles are bonded to the bearing alloy layer 6 and the solid lubricant plate crystal particles are firmly bonded to each other.
When the binder resin is a thermoplastic resin, the binder resin powder is heated to a semi-molten state or a molten state, and then solidified by cooling the jig with water, for example.

  Next, examples of the present invention will be described. A bimetal in which an aluminum-based bearing alloy layer (for example, Al-12 mass% Sn-3 mass% Si-1 mass% Cu) is lined on the back metal layer is manufactured, and a strip-shaped piece is obtained from the bimetal. After bending into a cylindrical shape, the surface of the bearing alloy layer was finished by boring, and samples of Example products 1 to 5 and Comparative products 1 to 4 were manufactured. And about each sample of Example goods 1-5 and comparative example goods 1, the solid lubricant plate-like crystal particle shown in the following table 1 is laminated with the adhesion device 10 shown in FIG. 3 with the resin powder for binders shown in the same table. Then, a coating layer having a thickness of about 8 μm was formed as described above.

For Comparative Example Product 2, a solid lubricant plate crystal particle (molybdenum disulfide) was collided with the bearing alloy layer by a shot blasting apparatus to form a coating layer having a thickness of about 0.1 μm. In the shot blast method, the thickness of the coating layer cannot be increased so much, and since the binder resin powder having a specific gravity different from that of the solid lubricant plate crystal particles cannot be simultaneously blasted, there is no binder resin in the coating layer. Not.
For the comparative product 3, only the solid lubricant plate crystal particles (graphite) shown in Table 1 were laminated by the attaching device 10 shown in FIG. 3 to form a coating layer having a thickness of about 8 μm.
For the comparative product 4, the coating layer was not provided, and the surface of the bearing alloy layer was a sliding surface in contact with the counterpart material.

  For Examples 1 to 5 and Comparative Examples 1 to 3, the orientation index of the (00l) plane of the solid lubricant plate crystal particles on the surface of the coating layer was determined by an X-ray diffraction intensity test. In addition, with respect to Example products 1 to 5 and Comparative product 1 to 4, a wear test was performed, and the remaining amount of the coating layer (the thickness of the coating layer remaining after wear) and the friction coefficient after 4 hours from the start of the test were determined. It was measured. The measured orientation index, residual amount and coefficient of friction are shown in Table 1. The friction test was conducted using a friction and wear tester. The friction test conditions are shown in Table 2 below.

  An example of the measurement result of the X-ray diffraction intensity test of the example product and the comparative example product is shown in FIGS. 8A, 8B, 9A, and 9B, respectively. FIG. 8 shows the measurement results of Example Product 1, FIG. 8B is a partially enlarged view of FIG. 9A, and FIG. 9 shows the measurement results of Comparative Product 2, and FIG. ) Is a partially enlarged view of FIG. 8 (a), (b) and FIGS. 9 (a), (b), the circles (circles) indicate the (00l) plane of molybdenum disulfide, which is a solid lubricant plate crystal particle, and Δ (triangle) Indicates a crystal plane of the bearing alloy layer, and x (cross) indicates a crystal plane other than the (00l) plane of molybdenum disulfide.

  As is clear from FIGS. 8A and 8B, the measurement result of Example Product 1 hardly shows any peaks other than the (00l) plane of the solid lubricant plate crystal particles. On the other hand, as is clear from FIGS. 9A and 9B, peaks other than the (00l) plane of the solid lubricant plate-like crystal particles are easily seen in the measurement result of Comparative Example Product 2. As shown in FIG. 9B, in the measurement result of the comparative product 1, the (101), (102), and (103) planes other than the (001) plane were identified.

  Regarding the orientation index, the comparative product 1 was less than 90%. This is because the amount of the binder resin exceeds 10% by mass, and the amount of the binder resin is large at the time of forming the coating layer, so that the orientation of the solid lubricant plate crystal particles is hindered by the binder resin. This seems to be the cause. Moreover, in the coating layer formed by shot peening of Comparative Example Product 2, the orientation index of the solid lubricant plate crystal particles is less than 90%. This is because in shot peening, it is difficult to align the orientation of the solid lubricant plate crystal particles.

  Consider the results of the wear test. First, in terms of the amount of wear, the example products 1 to 5 are smaller than the comparative example product 3 in which the coating layer is formed by the same method. This is considered to be because the strength of the coating layer was improved and the wear resistance was increased by including the binder resin. In addition, since the coating layer of the comparative example product 2 was completely worn out, the remaining amount was zero.

Next, looking at the friction coefficient, the comparative product 4 has a high friction coefficient. Since the comparative example product 4 does not have a coating layer, sliding between the mating shaft and the bearing alloy layer, that is, metal contact occurred frequently, and it is considered that the friction coefficient was high.
Among the samples having the coating layer, the example products 1 to 5 have a lower coefficient of friction than the comparative example products 1 to 4. Since this friction coefficient is 4 hours after the start of the friction test, it is clear that Examples 1 to 5 maintain low friction for a long time. The low friction coefficients of the example products 1 to 5 are due to the fact that the orientation index of the solid lubricant plate crystal particles is 90% or more, and the lubricating function of the solid lubricant plate crystal particles is sufficiently exhibited. it is conceivable that.

  In addition, the friction coefficients of the example products 1 to 5 are equivalent to those of the comparative example product 3 in which the coating layer is formed by the same method without using the binder resin. This is because the addition of 10% by mass or less of the binder resin does not adversely affect the lubricating function of the solid lubricant plate crystal particles, and the binder resin bonds the solid lubricant plate crystal particles to each other for a long time. It is considered that the low friction coefficient is maintained. As for the amount of binder resin added, Comparative Example Product 1 having a binder resin amount as large as 11% by mass has a low orientation index of less than 90%, and thus the friction coefficient is high. The amount is 10% by mass or less.

Sectional drawing which conceptually shows the layer structure of the solid lubricant plate crystal particles in the coating layer Partial sectional view of plain bearing Cross section of adhesion device Side view of plain bearing Bimetal cross section Conceptual diagram showing the state of lamination of plate-like crystals of solid lubricant plate-like crystal particles Diagram showing the crystal structure of molybdenum disulfide The graph which shows the result of the X-ray diffraction intensity test of the coating layer of an Example goods The graph which shows the result of the X-ray-diffraction intensity test of the coating layer of a comparative example product

Explanation of symbols

  In the drawings, 4 is a sliding bearing (sliding member), 5 is a back metal layer, 6 is a bearing alloy layer (base material), 7 is a coating layer, 8 is a binder resin, 10 is an adhesion device, and 13 is an adhesion medium. .

Claims (6)

In a sliding member in which a coating layer having a sliding surface is attached to the substrate surface,
The coating layer includes 10% by mass or less of a binder resin for laminating solid lubricant plate crystal particles and bonding the solid lubricant plate crystal particles;
The solid lubricant plate crystal particles have a crystal structure in which (00l) planes (where l is an integer of 1 or more) are stacked in parallel, and at least the sliding surface has an orientation index of (00l) plane of 90. % Or more of the sliding member.   2. The sliding member according to claim 1, wherein the solid lubricant plate crystal particles are made of one or more of molybdenum disulfide, graphite, tungsten disulfide, boron nitride, and molybdenum trioxide.   The sliding member according to claim 1 or 2, wherein the binder resin is contained in the coating layer in an amount of 2 to 7% by mass.   4. The sliding member according to claim 1, wherein the binder resin is made of a thermoplastic resin or a thermosetting resin. In the sliding member coating layer forming method according to any one of claims 1 to 4,
The solid lubricant plate-like crystal particles having a crystal structure in which (00l) planes are stacked in parallel to the adhesion medium are freely adhered together with the binder resin powder,
The solid lubricant plate-like crystal is slid by sliding the adhesion medium on which the solid lubricant plate-like crystal particles and the binder resin powder are freely adhered while applying pressure to the substrate surface. Adhering together with the powder of the binder resin while rubbing the solid lubricant plate-like crystal particles on the surface of the substrate so that the (00l) plane of the particles is parallel to the surface of the substrate;
Further, the solid lubricant is slid onto the surface of the solid lubricant plate-like crystal particles by sliding the adhesion medium on the surface of the solid lubricant plate-like crystal particles attached to the substrate surface while applying pressure. While laminating and laminating plate crystal particles together with the binder resin powder,
When the solid lubricant plate crystal particles and the binder resin powder are adhered, the binder is heated to generate frictional heat by adjusting the sliding speed of the adhesion medium. A method for forming a coating layer for a sliding member, wherein the resin powder is impregnated between the solid lubricant plate crystal particles in a semi-molten or molten state. The binder resin powder is composed of a thermosetting resin powder,
6. The method for forming a coating layer of a sliding member according to claim 5, wherein the binder resin is impregnated between the solid lubricant plate crystal particles, and then the binder resin is heated and cured.

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